/*
 * Copyright 2023 CloudWeGo Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * MIT License
 *
 * Copyright (c) 2019-present Fenny and Contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * This file may have been modified by CloudWeGo authors. All CloudWeGo
 * Modifications are Copyright 2023 CloudWeGo Authors
 */

package binding

import (
	"fmt"
	"reflect"
	"unsafe"
)

func valueAndTypeID(v interface{}) (reflect.Value, uintptr) {
	header := (*emptyInterface)(unsafe.Pointer(&v))
	rv := reflect.ValueOf(v)
	return rv, header.typeID
}

type emptyInterface struct {
	typeID  uintptr
	dataPtr unsafe.Pointer
}

func checkPointer(rv reflect.Value) error {
	if rv.Kind() != reflect.Ptr || rv.IsNil() {
		return fmt.Errorf("receiver must be a non-nil pointer")
	}
	return nil
}

func dereferPointer(rv reflect.Value) reflect.Type {
	rt := rv.Type()
	for rt.Kind() == reflect.Ptr {
		rt = rt.Elem()
	}
	return rt
}
